1. Field of the Invention
The present invention relates to an ink jet recording head, and a me hod for manufacturing an ink jet recording head.
2. Related Background Art
A liquid discharge recording apparatus is a recording apparatus of the so-called non-impact recording type which can perform recording at high speed and use various kinds of recording mediums for recording. Then, it is characterized in that almost no noise is generated at the time of recording. For the liquid discharge recording methods adoptable for a liquid discharge recording apparatus of this kind, there is, as the typical example thereof, a method that uses an electrothermal converting device as a discharge energy generating element. The liquid discharge recording head that uses this method provides an electrothermal converting device in each pressure chamber, and provides thermal energy for recording liquid when the electric pulses, which serve as recording signals, are applied to electrothermal converting devices. This generates a change of state of the recording liquid, and then, the bubbling pressure of the recording liquid exerted at the time of bubbling (at the time of boiling) is utilized for discharging recording liquid droplets.
Further, of the liquid discharge recording heads that use the electrothermal converting method, there are the one that adopts the method in which recording liquid is discharged in parallel to the base plate having the electrothermal converting devices arranged therefor (edge shooter) and the one that adopts the method in which recording liquid is discharged perpendicularly to the base plate having the electrothermal converting devices arranged therefor (side shooter).
FIG. 17 is a view which shows the state where the recording element base plate, which constitutes the background art of the application hereof, is mounted on a supporting member.
As shown in FIG. 17, a plurality of discharge ports 104a for discharging recording liquid are arranged on the discharge port plate 104 provided for the recording element base plate 103 on a surface thereof to be open in two lines in a position facing the discharge energy generating elements (electrothermal converting devices, for example) 105, and the discharge port array is structured to form a pair of lines. The recording liquid supply path 101a has a flow path width larger than the opening width of the inlet portion of the recording liquid supply port 106. As a result, the thickness of a partition wall 101b that partitions two recording supply paths 101a adjacent to each other is smaller than the pitch between the inlet portions themselves of two recording liquid supply ports 106 adjacent to each other.
There have been known several assembling methods or the like used for the manufacture of such recording element base plate as described above and the liquid discharge head that includes such base plate.
For example, in the specification of Japanese Patent Laid-Open Application No. 09-187952, an assembling method is disclosed to position the recording element base plate with respect to a method for manufacturing a liquid discharge head. This assembling method is such as to position the recording element base plate in good precision by use of vacuum adsorption fingers, and then, to fix the recording element base plate by the application of a bonding agent of the type that dually uses ultraviolet and thermal hardening.
Also, in the specification of Japanese Patent Laid-Open Application No. 11-179923, a method is disclosed for bonding an orifice plate (discharge port plate) to the main body of a liquid discharge head.
Also, in the specification of Japanese Patent Laid-Open Application No. 11-188873, a method is disclosed for bonding a nozzle member to the main body of a liquid discharge head which is provided with a plurality of ink chambers.
Of the recording element base plates described above, the second recording element base plate 103, which is provided with a plurality of discharge port arrays, in particular, makes it necessary to narrow the pitch between adjacent recording liquid supply ports 106 in a case where the number of recording element base plates is increased to implement a cost reduction when the base plates are cut out from one silicon wafer or where the number of discharge port arrays is increased without making the recording element base plate larger.
If the pitch between recording liquid supply ports 106 is made smaller, there is a need for making the thickness of the partition wall 101b of the supporting member 101 smaller accordingly. However, if the partition wall 101b is made thinner, there are problems that may be encountered as noted below.
(1) It is difficult to form the ceramic supporting member 101 with thin partition walls less than a certain thickness, from the viewpoint of manufacture.
(2) If the partition walls 101b are thin, vibration waves are propagated to adjacent supply flow paths through the partition walls 101b when recording liquid is discharged. Then, in the adjacent supply flow paths, the supply of the recording liquid becomes defective due to the propagated vibrations, resulting in defective printing.
(3) Further, if the partition walls 101b are thin, it becomes necessary to make the assembling precision higher for the recording element base plate 103 in relation to the supporting member 101 so as not to allow the adjacent supply flow paths 10a themselves to mix recording liquids.
On the other hand, if the partition walls 101b are made too thick, the width of the supply flow paths 101a becomes narrower, making it impossible to supply recording liquid to the recording liquid supply ports 106 in a sufficient amount.
Therefore, if the pitch between the recording supply ports themselves is to be made smaller, it is necessary to determine the thickness of the partition walls 101b to be formed in the supporting base plate 101 and the width of the supply flow paths 101a in consideration of those aspects described above.
Also, for the assembling method or the like described above, which is used for the manufacture of the recording element base plate and the manufacture of the liquid discharge head that includes that of the recording element base plate, the following drawback is encountered:
(1) Regarding the locations having coated thereon the dual type bonding agent of ultraviolet and thermal hardening, the irradiated ultraviolet rays do not reach the locations in the shadow of the adsorption fingers that adsorb the recording element base plate. As a result, the recording element base plate is transferred to the next hardening process while the positioning fixation has not been completed, and the positioning of the recording element base plate is deviated eventually.
(2) The viscosity of the dual type bonding agent of ultraviolet and thermal hardening on the locations where irradiated ultraviolet rays do not reach as described above is made extremely low immediately before hardening in the thermal harding step, and then, due to capillary force, the bonding agent is transferred to the corner portions inside the recording liquid flow path. As a result, the discharge nozzles become clogged.